Self-monitoring has been described as the cornerstone of the behavioral treatment of obesity . Consistent self-monitoring of energy intake is associated with improved dietary adherence and weight loss and maintenance. The problem is that individuals are notoriously bad at self-monitoring their intake and suffer from an underreporting bias. The significance of the proposed work is that it will make a low-cost intake monitoring device widely available for use in behavioral weight loss treatment and research. Our innovative intake monitoring method uses sensors embedded into a watch-like device to automatically track wrist motion to count bites and provide intake feedback during a meal, allowing individuals to self-monitor intake anywhere and anytime. In Phase 1, the method was shown to accurately count bites across a wide variety of foods, utensils and subject demographics, and to provide an unbiased intake measurement. Additional studies show people will use the device long-term and prefer our method over a manual method. The proposed work will continue to improve the bite counting method by adapting to varying eating rates, develop a self-managed bite count based weight loss protocol, and perform an independent test of the protocol.